Peter Orszag shares my enthusiasm for personal genomics and life-logging, which is heartening. But we think about the issue in very different ways. I see it as a way for consumers to do an end-run around overpriced medical providers.

A longer-term worry is that the new technologies may widen gaps in life expectancy. Americans are living longer than ever — but, as documented in a recent National Academy of Sciences report (“Explaining Divergent Levels of Longevity in High-Income Countries”), people with more education and income are enjoying much more rapid increases in longevity than others are. …

If the new personalized health technologies wind up being used disproportionately by people with more education and income, driving that group toward even better health, they will probably cause the gap in life expectancy to widen still further.

The true health-improving potential of devices such as the VITAband and the Fitbit will be realized only if they are used by those who most need to change their health behavior — the same people who have been lagging in life expectancy. If not, just as technology has helped expand income inequality over the past four decades, it may likewise play a major role in expanding life-span inequality.

I’m not worried about this divergence. I think it is a safe bet that as affluent consumers embrace these technologies in growing numbers, other consumers will follow. This will take time. But these are technologies that require a high degree of “buy-in.” Just as people value bed-nets more when they pay for them with their own money, I suspect that any campaign of hectoring, or any decision to distribute these tools for free or at a steeply discounted price, will prove to be of limited utility. Moreover, a public campaign devoted to spreading these technologies among the reluctant might lead public officials to favor a platform that wouldn’t flourish independently, and that is owned by the politically connected.

Orszag wasn’t calling for an industrial policy approach to life-logging, as far as I can tell, but let’s just nip that idea in the bud.

And while I think extending healthy lifespan is an important public policy goal, I’m not sure the lens of social justice is the best way to look at how healthy lifespan diverges across individuals. Orszag writes:

Among 50-year-old men, for example, those in the highest education group are now projected to live almost six years longer on average than those in the lowest education group — and this differential has been rising sharply. The widening gap in life expectancy is also evident geographically. In 2007, men living in the American counties with the greatest average longevity could expect to live more than 15 years longer than men in the lowest- ranked ones. In 1987, that gap was less than 12 years. Sadly, life expectancy in some counties actually declined over that period.

The leading explanations for this involve health behavior — including diet, exercise and smoking. For example, men 50 and older without a high-school education are more than twice as likely to smoke as those with a college degree. Exercise behavior also varies substantially. Among 45- to 54-year-olds in one study, only 16 percent of those without a high-school degree exercised vigorously at least once a week, whereas 56 percent of college graduates did.

Affluence and education can serve as a proxy for behavior. Public policy can influence behavior, and I’m not opposed to public health paternalism in every instance just as I am open to some forms of redistribution. I imagine that Orszag and I would agree that it makes sense for us to collectively provide opportunities for education and other means of social advancement. But at some point it is important to accept that we live in a diverse society, and that different people have different proclivities that will influence their life chances.